Thank you for the information,
The white blisters can be due to some common causes.The common ones are canker sores or aphthous ulcers, oral warts, leukoplakia, hairy tongue, geographic tongue, etc.
The most common cause is the aphthous ulcers or canker sores which may be due to the viral infection, deficiency of vitamin and folic acid, autoimmune, etc.The causes are idiopathic in most of the cases.The exact cause of aphthous ulcers is not known.
You should get enough fruits and begetables in diet and the vitamins supplementation.The oral application of chlorhexidine or other antiseptic solution will help you in controlling the symptoms.You may use the local anaesthetic solution like dologel, etc. for immediate relief of the symptoms.
The oral warts caused by HPV virus can also cause such painful blisters and is related to oral sexual contact.The treatment of viral infection is symptomatic and antiviral drugs are used in severe cases.
You should consult a doctor or ENT specialist for the proper physical examination and relevant investigations if your symptoms are not controlled.
The treatment depends o the underlying cause.
Please visit here for more information:
causes of mouth ulcers
Let me know if you have any doubt.